在上一篇如何使用ASP.NET Core、EF Core、ABP(ASP.NET Boilerplate)创建分层的Web应用程序（第一部分）我们介绍了第一部分，这一篇是接着上一篇的内容写的。
创建Person实体
添加一个Person实体，用于分配任务：
[Table("AppPersons")] ??public class Person:AuditedEntity<Guid> ???{ ???????public const int MaxNameLength = 32; ???????[Required] ???????[MaxLength(MaxNameLength)] ???????public string Name { get; set; } ???????public Person() ???????{ ???????} ???????public Person(string name) ???????{ ???????????Name = name; ???????} ???}这次我设置主键Id的类型为Guid，为了进行演示，Person类继承了AuditedEntity(它具有CreationTime、CreaterUserId、LastModificationTime和LastModifierUserId属性)。
关联Person与Task
向Task实体添加了AssignedPerson属性
?[Table("AppTasks")] ???public class Task : Entity, IHasCreationTime ???{ ???????public const int MaxTitleLength = 256; ???????public const int MaxDescriptionLength = 64 * 1024; //64KB ???????[ForeignKey(nameof(AssignedPersonId))] ???????public Person AssignedPerson { get; set; } ???????public Guid? AssignedPersonId { get; set; } ???????[Required] ???????[MaxLength(MaxTitleLength)] ???????public string Title { get; set; } ???????[MaxLength(MaxDescriptionLength)] ???????public string Description { get; set; } ???????public DateTime CreationTime { get; set; } ???????public TaskState State { get; set; } ???????public Task() ???????{ ???????????CreationTime = Clock.Now; ???????????State = TaskState.Open; ???????} ???????public Task(string title, string description = null,Guid? assignedPersonId=null) ???????????: this() ???????{ ???????????Title = title; ???????????Description = description; ???????????AssignedPersonId = assignedPersonId; ???????} ???}AssignedPerson是可选的。因此，任务可以分配给一个人，也可以不分配。
添加Person到DbContext
public DbSet<Person> People { get; set; }为Person实体添加新的迁移
在包管理器控制台执行以下命令
它在项目中创建了一个新的迁移类
using System;using Microsoft.EntityFrameworkCore.Migrations;namespace Acme.SimpleTaskSystem.Migrations{ ???public partial class Added_Person : Migration ???{ ???????protected override void Up(MigrationBuilder migrationBuilder) ???????{ ???????????migrationBuilder.AddColumn<Guid>( ???????????????name: "AssignedPersonId", ???????????????table: "AppTasks", ???????????????nullable: true); ???????????migrationBuilder.CreateTable( ???????????????name: "AppPersons", ???????????????columns: table => new ???????????????{ ???????????????????Id = table.Column<Guid>(nullable: false), ???????????????????CreationTime = table.Column<DateTime>(nullable: false), ???????????????????CreatorUserId = table.Column<long>(nullable: true), ???????????????????LastModificationTime = table.Column<DateTime>(nullable: true), ???????????????????LastModifierUserId = table.Column<long>(nullable: true), ???????????????????Name = table.Column<string>(maxLength: 32, nullable: false) ???????????????}, ???????????????constraints: table => ???????????????{ ???????????????????table.PrimaryKey("PK_AppPersons", x => x.Id); ???????????????}); ???????????migrationBuilder.CreateIndex( ???????????????name: "IX_AppTasks_AssignedPersonId", ???????????????table: "AppTasks", ???????????????column: "AssignedPersonId"); ???????????migrationBuilder.AddForeignKey( ???????????????name: "FK_AppTasks_AppPersons_AssignedPersonId", ???????????????table: "AppTasks", ???????????????column: "AssignedPersonId", ???????????????principalTable: "AppPersons", ???????????????principalColumn: "Id", ???????????????onDelete: ReferentialAction.SetNull); ???????} ???????protected override void Down(MigrationBuilder migrationBuilder) ???????{ ???????????migrationBuilder.DropForeignKey( ???????????????name: "FK_AppTasks_AppPersons_AssignedPersonId", ???????????????table: "AppTasks"); ???????????migrationBuilder.DropTable( ???????????????name: "AppPersons"); ???????????migrationBuilder.DropIndex( ???????????????name: "IX_AppTasks_AssignedPersonId", ???????????????table: "AppTasks"); ???????????migrationBuilder.DropColumn( ???????????????name: "AssignedPersonId", ???????????????table: "AppTasks"); ???????} ???}}我仅仅将ReferentialAction.Restrict 改变为ReferentialAction.SetNull.这样的话，当我们删除一个人，那么分配给那个人的任务就会被设置成未分配。这个 在本次教程中并不重要，但是可以说明如果有需要的情况下，我们是可以修改迁移类中的代码的。事实上，我们应该每次都检查一下迁移代码之后再将其应用到数据库。
打开数据库可以看到新加的表和列，这里可以加一些测试数据：
我们将第一个任务分配给第一个人：
在任务列表中返回分配的人员
将TaskAppService更改为返回分配的人员信息。首先，向TaskListDto添加两个属性:
public Guid? AssignedPersonId { get; set; }public string AssignedPersonName { get; set; }将Task.AssignedPerson属性添加到查询方法中，只添加Include行：
public async Task<ListResultDto<TaskListDto>> GetAll(GetAllTasksInput input) ???????{ ???????????var tasks = await _taskRepository ???????????????.GetAll() ???????????????.Include(t => t.AssignedPerson) ???????????????.WhereIf(input.State.HasValue, t => t.State == input.State.Value) ???????????????.OrderByDescending(t => t.CreationTime) ???????????????.ToListAsync(); ???????????return new ListResultDto<TaskListDto>( ???????????????ObjectMapper.Map<List<TaskListDto>>(tasks) ???????????); ???????}这样，GetAll方法将返回分配给任务的人员信息。由于我们使用了AutoMapper，新的属性也将自动复制到DTO。
在任务列表页面显示被分配的人员姓名
我们在Tasks\Index下可以修改index.cshtml来显示AssignedPersonName:
@foreach (var task in Model.Tasks) ???????????{ ???????????????<li class="list-group-item"> ???????????????????<span class="pull-right label @Model.GetTaskLabel(task)">@L($"TaskState_{task.State}")</span> ???????????????????<h4 class="list-group-item-heading">@task.Title</h4> ???????????????????<div class="list-group-item-text"> ???????????????????????@task.CreationTime.ToString("yyyy-MM-dd HH:mm:ss")|@(task.AssignedPersonName?? L("Unassigned")) ???????????????????</div> ???????????????</li> ???????????}运行程序，可以看到被分配的任务会显示人员姓名;
创建任务
前面的内容都是显示任务列表，接下来我们要做一个创建任务的页面。首先在ITaskAppService 接口中增加Create方法;
System.Threading.Tasks.Task Create(CreateTaskInput input);
在TaskAppService 类中实现它：
public async System.Threading.Tasks.Task Create(CreateTaskInput input) ???????{ ???????????var task = ObjectMapper.Map<Task>(input); ???????????await _taskRepository.InsertAsync(task); ???????}创建CreateTaskInput Dto如下所示：
[AutoMapTo(typeof(Task))] ???public class CreateTaskInput ???{ ???????[Required] ???????[MaxLength(Task.MaxTitleLength)] ???????public string Title { get; set; } ???????[MaxLength(Task.MaxDescriptionLength)] ???????public string Description { get; set; } ???????public Guid? AssignedPersonId { get; set; } ???}配置将其映射到任务实体(使用AutoMapTo属性)并添加数据注释以应用验证，这里的长度和Task实体中的长度一致。
----省略单元测试的内容-----
创建任务页面
首先在TaskController 中添加Create action
??public class TasksController : SimpleTaskSystemControllerBase ???{ ???????private readonly ITaskAppService _taskAppService; ???????private readonly ILookupAppService _lookupAppService; ???????public TasksController(ITaskAppService taskAppService, ILookupAppService lookupAppService) ???????{ ???????????_taskAppService = taskAppService; ???????????_lookupAppService = lookupAppService; ???????} ???????public async Task<ActionResult> Index(GetAllTasksInput input) ???????{ ???????????var output = await _taskAppService.GetAll(input); ???????????var model = new IndexViewModel(output.Items) ???????????{ ???????????????SelectedTaskState = input.State ???????}; ???????????return View(model); ???????} ???????public async Task<ActionResult> Create() ???????{ ???????????var peopleSelectListItems = (await _lookupAppService.GetPeopleComboboxItems()).Items ???????????????.Select(p => p.ToSelectListItem()) ???????????????.ToList(); ???????????peopleSelectListItems.Insert(0, new SelectListItem { Value = string.Empty, Text = L("Unassigned"), Selected = true }); ???????????return View(new CreateTaskViewModel(peopleSelectListItems)); ???????} ???}我注入了ILookupAppService 以获得人员列表，虽然这里可以直接使用IRepository<Person, Guid>，但是这样可以更好的分层和重用，ILookupAppService.GetPeopleComboboxItems 定义在应用层：
public interface ILookupAppService:IApplicationService ???{ ???????Task<ListResultDto<ComboboxItemDto>> GetPeopleComboboxItems(); ???}public class LookupAppService:SimpleTaskSystemAppServiceBase,ILookupAppService ???{ ???????private readonly IRepository<Person, Guid> _personRepository; ???????public LookupAppService(IRepository<Person, Guid> personRepository) ???????{ ???????????_personRepository = personRepository; ???????} ???????public async Task<ListResultDto<ComboboxItemDto>> GetPeopleComboboxItems() ???????{ ???????????var people = await _personRepository.GetAllListAsync(); ???????????return new ListResultDto<ComboboxItemDto>( ???????????????people.Select(p => new ComboboxItemDto(p.Id.ToString("D"), p.Name)).ToList() ???????????); ???????} ???}ComboboxItemDto是一个简单的类(在ABP中定义)，用于传输combobox项数据。TaskController.Create用这个方法将返回的List转换成SelectListItem列表(在AspNet .Core中定义),并通过CreateTaskViewModel传递到视图：
public class CreateTaskViewModel ???{ ???????public List<SelectListItem> People { get; set; } ???????public CreateTaskViewModel(List<SelectListItem> people) ???????{ ???????????People = people; ???????} ???}创建视图代码如下：
@model Acme.SimpleTaskSystem.Web.CreateTaskViewModel@section scripts{ ???<environment names="Development"> ???????<script src="~/js/views/tasks/create.js"></script> ???</environment> ???<environment names="Staging,Production"> ???????<script src="~/js/views/tasks/create.min.js"></script> ???</environment>}<h2> ???@L("NewTask")</h2><form id="TaskCreationForm"> ???<div class="form-group"> ???????<label for="Title">@L("Title")</label> ???????<input type="text" name="Title" class="form-control" placeholder="@L("Title")" required maxlength="@Acme.SimpleTaskSystem.Task.MaxTitleLength"> ???</div> ???<div class="form-group"> ???????<label for="Description">@L("Description")</label> ???????<input type="text" name="Description" class="form-control" placeholder="@L("Description")" maxlength="@Acme.SimpleTaskSystem.Task.MaxDescriptionLength"> ???</div> ???<div class="form-group"> ???????@Html.Label(L("AssignedPerson")) ???????@Html.DropDownList( ???????????"AssignedPersonId", ???????????Model.People, ???????????new ???????????{ ???????????????@class = "form-control", ???????????????id = "AssignedPersonCombobox" ???????????}) ???</div> ???<button type="submit" class="btn btn-default">@L("Save")</button></form>创建 create.js如下：
(function ($) { ???$(function () { ???????var _$form = $(‘#TaskCreationForm‘); ???????_$form.find(‘input:first‘).focus(); ???????_$form.validate(); ???????_$form.find(‘button[type=submit]‘) ???????????.click(function (e) { ???????????????e.preventDefault(); ???????????????if (!_$form.valid()) { ???????????????????return; ???????????????} ???????????????var input = _$form.serializeFormToObject(); ???????????????abp.services.app.task.create(input) ???????????????????.done(function () { ???????????????????????location.href = ‘/Tasks‘; ???????????????????}); ???????????}); ???});})(jQuery);create.js做了如下事情：
- 为表单准备验证(使用jquery验证插件)，并在Save按钮的单击时验证它
- 使用serializeFormToObject jquery插件(在jquery扩展中定义)。将表单数据转换为JSON对象，(Layout.cshtml中引入了 jquery-extensions.js)。
- 用 abp.services.task.create方法去调用TaskAppService.Create方法。这是ABP中的一个重要的特性，我们可以在JavaScript中调用应用程序服务方法，就像调用JavaScript方法一样
最后在任务列表中增加“Add Task”按钮以作为增加任务的入口：
<a class="btn btn-primary btn-sm" asp-action="Create">@L("AddNew")</a>运行程序到创建任务页面，可以看到页面如下所示：
到这我们就可以填写信息点击Save按钮保存即可哦。
注：如果不需要Home或者About的直接去掉就可以，ABP框架很灵活，就根据自己的需求修改就ok了。
如何使用ASP.NET Core、EF Core、ABP(ASP.NET Boilerplate)创建分层的Web应用程序（第二部分）
原文地址：https://www.cnblogs.com/yixuanhan/p/9425015.html